Do you consider yourself to be an observant kind of person? Someone who really pays attention to detail? If you are, then you’ll be interested in watching and participating in a couple of video tests by researchers Christopher Chabris and Daniel Simons. These are genuine experiments – there’s no skull or shriek going to pop out half way through.

The first is a over ten years old and is considered to be a classic – just follow the instructions. It’s best if you can run it full-screen.

Now, if you’ve seen that one before, or if you want to try it for a second time, you can watch this newer version. Again just follow the instructions and also best viewed full-screen.

If you’ve been totally fascinated by what you’ve just seen, then head on over to the source site here or the YouTube Channel for more videos.